1. Field of the Invention
The present invention relates to alight emitting diode driver, and more particularly, to a light emitting diode driver removing signal interference by varying a switching frequency within a preset range.
2. Description of the Related Art
In recent years, new flat panel display (FPD) technologies, reflecting the demand for high resolution, large-sized screens and the like in the present multimedia age, have become prominent in the display industry. Particularly, in the case of a medium- and large-sized display, a Liquid Crystal Display (LCD) TV has shown a rapid growth and an LCD monitor has been adopted in laptop computers, and accordingly, an LCD has been expected to grow in prominence henceforth, in view of price and marketability.
A Cold Cathode Fluorescent Lamp (CCFL) has been used as a backlight light source in an LCD TV or a notebook according to the related art. In recent years, however, the use of a Light Emitting Diode (LED) has been gradually increased due to various advantages including power consumption, life span and environmentally friendly characteristics.
In the case of a medium- and large-sized display, such an LED includes a plurality of LED channels. In order to control each of the LED channels with a constant current, a switch device that supplies current to the LED channels according to a preset switching frequency is used.
However, a constant frequency of the switch device may generate harmonic waves, such that signal interference caused by the harmonic waves may cause a system malfunction problem.